US2100834A

US2100834A - Air conditioning system

Info

Publication number: US2100834A
Application number: US93645A
Authority: US
Inventors: Robert L Chapman
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1936-07-31
Filing date: 1936-07-31
Publication date: 1937-11-30
Anticipated expiration: 1954-11-30

Description

Nov. 30, 1937.

R. L. CHAPMAN 2,100,834 I AIR CONDITIONING SYSTEM 2 Sheets-Sheet 2 Filed July 31, 1936 Inventor Robert I... Chapman,

Patented Nov. 30, 1937 PATENT OFFICE AIR CONDITIONING SYSTEM Robert L. Chapman, Erie, Pa., assignor to General Electric Company, a corporation of New York 'Application July 31, 1936, Serial No. 93,645

10 Claims.

My invention relates to air conditioning systems of the type utilizing mechanical refrigerating machines, and particularly to such systems employed for cooling the air in the passenger space of a railway car or other vehicle.

-Modern railway cars are commonly provided with air conditioning systems for maintaining the air within the-passenger space of the car sufficiently cooled to provide adequate comfort for the passengers on hot summer days. Since the refrigerating equipment must be carried by the railway car, the capacity thereof is limited because of space, weight and power restrictions. It has been found that in order to provide air in the passenger space which is not objectionable because of odor or staleness, it is necessary to admit a considerable quantity of fresh air to the car and, consequently, an equal quantity of vitiated air must be exhausted from the car. This exchange of fresh for vitiated air represents some loss of cooling effect, since the fresh air is normally at a considerably higher temperature than the exhausted stale air, and it is, therefore, necessary to provide additional refrigerating capacity to make up for this loss. Accordingly, it is an object of my invention to provide an air conditioning system including an enclosure to be conditioned and provided with a refrigerating machine having a condenser and an evaporator and arranged to utilize the cooling capacity of air discharged from the enclosure to increase the effective capacity of a refrigerating machine.

Another object of my invention is to provide a system for conditioning the air within the passenger space of a vehicle employing a mechanical refrigerating maciine including a condenser and an evaporator for cooling the air of the passenger space, and an arrangement whereby air exhausted from the passenger space is utilizedfor subcooling refrigerant liquefied in the condenser.

A further object of my invention is to provide a system for conditioning the air within the passenger space of a. vehicle and utilizing a refrigerating machine, having a condenser, a liquid subcooler and an evaporator and in which air exhausted from the passenger space is directed through a duct to cool the liquid subcooler and a portion of the condenser.

Further objects and advantages of my inven tion will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention,

reference may be had to the accompanying drawings in which Fig. l is a side elevation, partly in section, of a portion of a railway car provided with an air conditioning system embodying my invention; Fig. 2 is a view similar to that shown 5 in Fig. 1, illustrating another modification of my invention; and Fig. 3 is an end view, partly in section, of the motor and compressor housing and exhaust air duct shown in Fig. 2.

Referring now to the drawings in Fig. l, I have shown one end of a passenger railway car having a passenger compartment I0 and an entrance vestibule II connected by a corridor A compartment I3 is provided between the passenger space I0 and the vestibule II on one side of the car separated from the corridor I2 by a partition I4. Within the compartment I3 is arranged apparatus for circulating and cooling air and for delivering cooled air to the passenger space to condition the air therein. This apparatus comprises a duct I5 within which is arranged an evaporator or cooling element I6 and a fan H for circulating air through the duct over the evaporator and into a distributing duct I8. The duct I8 extends along the top of the car and is provided with a plurality of outlet openings I9 for discharging the conditioned air into the upper portion of the passenger space. Air from the passenger space is admitted to the duct I5 through an inlet at the lower end thereof, and fresh air is admitted to the duct I5 through a fresh air inlet opening 2| providing communication between the duct andthe air outside the car. The fresh air and the recirculated air are mixed before passing over the evaporator I6 and the mixture is then discharged from the duct I8 by operation of the fan I1 and flows out of the openings I9 and downwardly through the passenger space as indicated by the arrows. A portion of the air is returned to the duct I5 through the inlet 20 to be recirculated. In order to remove a quantity of the stale vitiated air an air discharge fan 22 is provided. This fan is arranged within a duct 23 in the compartment I3 and air from the the passenger space enters the duct 23 through an inlet 24 opening into the corridor I2 through the wall I4. This air withdrawn from the corridor passes through the duct 23 and is exhausted from the car by the operation of the fan 22, the exhausted air passing through a discharge opening 25 in the roof of the car. In order to provide refrigerant for cooling the evaporator I6 a condensing unit 26 is provided suspended from the lower side of the car on the outside thereof The condensing unit is shown mounted on the far side of the car, i. e., on the same side as the compartment l3. The condensing unit comprises a compressor 21 driven by a motor 28 and a condenser comprising

coil sections

29 and 30 mounted at either end of the unit and connected in parallel in the refrigerant circuit. The unit is provided with a sheet metal housing 3| and air is circulated through the housing and over the compressor and the condenser by operation of a fan 32 driven by the motor 28. Cooling air enters .the housing 3| through a circular opening 33 and passes through the housing and over the compressor 21 and condenser

sections

29 and 30 and thence out through openings 34 and 35, thereby cooling the compressor and the condenser.

During the operation of the condensing unit 26' gaseous refrigerant is withdrawn from the evaporator |5 through suction line 36 and is compressed within the compressor 21 and then discharged into a manifold connection 31 from which it flows in parallel to

sections

29 and 30 of the condenser. The cooling air circulated over the condenser sections by the fan 32 absorbs heat from the hot compressed refrigerant vaporand the vapor is cooled thereby and liquefied. The liquid refrigerant flows out of the

condenser sections

29 and 30 into a liquid manifold 38 from which it flows through a connection 39 into a liquid receiver 40.

The refrigerant liquefied in the receiver 40, although it has been cooled by the air passing over the condenser, is nevertheless at a temperature much higher than that in the enclosure to be conditioned, and it is desirable further to cool the liquid before admitting it to the evaporator, in order to prevent loss of cooling capacity due to the necessity of absorbing the heat of the liquid beyond the expansion valve. I have found that the heat absorbing capacity of the air exhausted from the passenger space may be utilized to advantage to cool the liquid refrigerant before it flows to the evaporator and thereby increase the effective capacity of the compressor. In Fig. 1, I have shown a heat exchange element 4| arranged in the duct 23 and connected in the refrigerant circuit between the liquid reeciver 40 and the evaporator. Liquid flows from the receiver 40 through a liquid line 42, passes through the heat exchange element or cooling coil 4|,

' then flows through a thermostatic valve or other place at the valve. The total heatabsorbing capacity of the refrigerating machine is, therefore,

increased without necessitating an increase in the capacity of the compressor 21.

The fans I! and 22 have been shown arranged on a single shaft 45 driven by a common motor 46. The motor 46 may be run continuously and thereby provide continuous ventilation of the passenger space by the addition of fresh air through the inlet 23 and the discharge of stale air through the outlet 25. The apparatus shown may be of suficient capacity to condition the entire car, or a separate identical system may be provided in the other end of the car, if desired.

In Figs. 2 and 3 I have shown another embodiment of my invention in which the air exhausted from the passenger space is utilized not only to subcool the liquid refrigerant, but is also mixed with the condenser cooling air. The condenser cooling fan isutilized also to exhaust the air from the passenger space and a separate exhaust fan is not necessary. The arrangement of the circulating and cooling apparatus within the car issubstantially the same as that shown in Fig. 1, except for the location of the exhaust air duct. Corresponding parts of the equipment, therefore, have been designated by the same numerals as used in Fig. 1 except for the parts of the exhaust air and sub-cooling apparatus.

Referring now to Fig. 2, I have shown a portion of one end of a passenger car provided with air cooling and circulating apparatus like that shown in Fig. 1. This apparatus includes the evaporator I6 arranged in duct l5 and the fan driven by the motor 46 for circulating, return and fresh air from the openings 20 and 2| over the evaporator l6 and into the passenger space through duct l8 and outlets Hi. In order to remove vitiated or stale air from the passenger compartment I provide an exhaust air duct or passage 41 passing through the floor of the car indicated at 48 and having an inlet opening 49 within the passenger space. The duct 41 is arranged adjacent the compressor condenser unit 26 which supplies refrigerant to the evaporator I6, and the duct is provided with an outlet 50 registering with the upper portion of the opening 33 in the compressor condenser housing 3|. Below the duct 41 is arranged a short horizontal passage 5| registering with the remaining portion of the opening 33 and provided with a guard screen 52. The condenser fan 32 draws air into the housing 3| from the outside through the passage 5| and from the passenger space through the duct 41. A heat exchange element 53 connected in the refrigerant circuit between the liquid receiver 40 and the expansion valve 43 is arranged within the duct 41 in the path of the exhausted stale air. The element 53 corresponds to the element 4| in Fig. l and functions in the same manner. During the operation of the refrigerating machine refrigerant compressed in the compressor 21 and liquefied in the

condenser sections

29 and 30 flows into the liquid receiver 40 and then through a connection 54 to the heat exchanger 53 where the liquid refrigerant is cooled by the passage of cool exhaust air through the duct 41. The cooled liquid refrigerant is then conveyed by a liquid line 55 to the expansion valve 43, which controls the flow of refrigerant to the evaporator I6. Liquid refrigerant in the evaporator I6 is vaporized by the absorption of heat from the mixture of fresh and recirculated air passing through the duct l5 and the vaporized refrigerant is withdrawn from the evaporator l6 through suction line 35 and returned to the compressor.

The cooled mixture of fresh and recirculated air is forced by operation of the fan I! through distribution duct l8 and into the passenger space through outlets IS, the path of the air being indicated by the arrows. The operation ,of the condenser fan 32 draws fresh air through the passage 5! and exhausted air through the passage 47 and forces the mixture of air through the

condenser sections

29 and 30. The exhausted air after passing over the heat exchange element 53 within the duct 41 is normally at a temperature lower than that of the fresh air drawn through'the passage and, consequently,

sub-cooling coil is arranged in a duct to heat condenser cooling air prior to its passage over the condenser is described and claimed in a copending application of Olaf M. Olson, Serial No. 93,613, filed July 31, 1936 and assigned to General Electric Company, assignee of my present invention. I do not therefore herein claim anything claimed in the said Olson application which is to be regarded as prior art with respect to the present application.

From the foregoing it is apparent that I have provided a simple and eflicient'arrangement for utilizing the heat absorbing capacity of stale air exhausted from an enclosure to be conditioned for increasing the effective capacity of the condensing unit of a mechanical refrigerating machine utilized for cooling the air in the enclosure. conditioning system which is particularly applicable to the cooling of the passenger spaces of vehicles such as railway cars.

While I have shown and described my invention in connection with an air conditioning system for railway passenger cars, it will be understood that it is applicable to other types of air conditioning systems. I do not, therefore, de-

sire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications thereof which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure'by Letters Patent of the United States is:

1. An air conditioning system including an enclosure to be conditioned, means for circulating air through said enclosure, a refrigerating machine having a refrigerant circuit including a condenser and an evaporator, means for circulating over said condenser cooling fluid from outside said enclosure to cool said condenser, said evaporator being arranged in the path of the air circulating through said enclosure, means for discharging air from said enclosure, and means includinga heat exchange element connected in the refrigerant circuit of said refrigerating machine between said condenser and said evaporator and arranged in the path of only the air discharged from said enclosure for cooling refrigerant liquefied in said condenser.

2. An air conditioning system including an enclosure to be conditioned and a duct communicating with said enclosure, means for circulating air through said duct and into said enclosure, a refrigerating machine having a refrigerant circuit including a condenser-and an evaporator, means for circulating over said condenser cooling fluid from outside said enclosure to cool said condenser, said evaporator being arranged in said duct to cool the air circulating therethrough, means for discharging aimfrom said enclosure, and means including a heat exchange element connected in the refrigerant -circuit of said refrigerating machine between said condenser and said evaporator and arranged in the path of only the air discharged from said enclosure for cooling refrigerant liquefied in said condenser.

3. An air conditioning system including an enclosure to be conditioned and a duct com- Furthermore, I have provided an air municating with said enclosure, means for circulating air through said duct and into said enclosure, a refrigerating machine having-a refrigerant circuit including a condenser and an evaporator, means for circulating over said cone denser cooling fluid from outside said enclosure to cool said condenser, said evaporator being arranged in said duct to cool the air circulating therethrough, means including a passage and a fan arranged therein for discharging air from said enclosure and means including a heat exchange element connected in the refrigerant circuit of said refrigerating machine between said condenser and said evaporator and arranged in said air discharge passage for cooling refrigerant liquefied on said condenser.

4. An air conditioning system including an enclosure to be conditioned and a duct communicating with said enclosure, means for circulating air through said duct and into said enclosure, a refrigerating machine having a refrigerant circult including a condenser and an evaporator, said evaporator being arranged in said duct to cool the air circulating therethrough, means for discharging air from said enclosure, means for circulating air from outside said enclosure over said condenser to cool said condenser, means including a heat exchange element connected in the refrigerant circuit of said refrigerating machine between said condenser and said evaporator and arranged in the path of only the air discharged from said enclosure for cooling refrigerant liquefied in said condenser, and means for directing said discharged air over said condenser to assist the cooling of said condenser.

5. An air conditioning system including an enclosure to be conditioned and a duct communicating with said enclosure, means for circulating air through said duct and into said enclosure, a refrigerating machine having a refrigerant circuit including a condenser, a liquid refrigerant receiver and an evaporator, means for circulating over said condenser cooling'fluid from outside said enclosure to cool said condenser, said evaporator being arranged in said duct to cool the air circulating, therethrough, means for discharging air from said enclosure, and means including a heat exchange element connected in the refrigerant circuit of said refrigerating machine between said liquid refrigerant receiver and said evaporator and arranged in the path of only the air discharged from said enclosure for cooling refrigerant liquefied in said condenser.

6. A system for conditioning the air within the passenger space of a vehicle including a refrigerating machine having a condenser and an evaporator connected in the refrigerant circuit thereof, means for circulating over said condenser cooling fluid from outside said enclosure to cool said condenser, means circulating air over said evaporator for cooling the air within said passenger space, means for discharging air from said passenger space, and means including a heat exchange element connected in said refrigerant circuit between said condenser and said evaporator and arranged in the path of only the air discharged from said passenger space for cooling refrigerant liquefied in said condenser.

I. A system for conditioning the air within the passenger space of a vehicle including a refrigerating machine having a condenser and an evaporator connected in the refrigerant circuit thereof, means for circulating over said condenser cooling fluid from outside said enclosure to cool said condenser, means circulating air over said evaporator for cooling the air within said passenger space, means for admitting to said air circulating means fresh air from outside said passenger space, means including a passage for discharging air from said passenger space, and means including a heat exchange element connected in said refrigerant circuit between said condenser and said evaporator and arranged in said passage for cooling refrigerant liquefied in said condenser.

8. A system for conditioning the air within the passenger space of a vehicle including a refrigerating machine having a condenser and an evaporator connected in the refrigerant circuit thereof, means including a duct and circulating air over said evaporator for cooling the air with- 1 in said passenger space, means admitting to said duct fresh air fromgoutside said passenger space, means including a passage solely for discharging air from said passenger space, means including a heat exchange element connected in said refrigerant circuit between said condenser and said evaporator and arranged in said passage for cooling refrigerant liquefied in said condenser, and means for circulating over said condenser air from outside said passenger space and said air discharged from said passenger space.

9. A system for conditioning the air within the passenger space of a vehicle including a refrigerating machine having a condenser and an evaporator connected in the refrigerant circuit thereof, means including a fan for circulating over said condenser air from outside said passenger space, means circulating air over said evaporator for cooling the air within said passenger space, means including a passage and utilizing said fan for discharging air from said passenger space, and means including a heat exchange element connected in said refrigerant circuit between said condenser and said evaporator and arranged m the path of only the air discharged from; said passenger space for cooling refrigerant liquefied in said condenser.

10. A system for conditioning the air within the passenger space of a vehicle including a refrigerating machine having a compressor and a condenser and an evaporator connected in the refrigerant circuit thereof, said compressor and said condenser being arranged outside said passenger space and on the underside of said vehicle, means including a housing and a fan for circulating air over said compressor and said condenser, means circulating air over said evaporator for cooling the air within said passenger space, means including a passage and utilizing said fan for discharging air from said passenger space, and

means including a heat exchange element connected in said refrigerant circuit between said condenser and said evaporator and arranged in said passage for cooling refrigerant liquefied in said condenser.

ROBERT L. CHAPMAN.

7 CERTIFICATE OF CORRECT-ION. Patent No. '2,lOO,83]+., 4 November 50, 1957.

ROBERT L. CHAPMAN,

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 second column, line 16, claim 5, for the word "an" read in; and that the said Let ters Patent should be read with this correction therein that the same may conform to the record of tne case in the Patent Office.

vSigned and sealed this lst day of February, A. D. 1958.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.